import java.util.Arrays;

/**
 * The sort method of this class sorts an array, using the selection sort
 * algorithm.
 */
public class SelectionSorter
{
    /**
     * Sorts an array, using selection sort.
     * @param a the array to sort
     */
    public static void sort(int[] a)
    {
        for (int i = 0; i < a.length - 1; i++) {
            int minPos = minimumPosition(a, i);
            ArrayUtil.swap(a, minPos, i);
        }
    }

    /**
     * Finds the smallest element in a tail range of the array.
     * @param a the array to sort
     * @param from the first position in a to compare
     * @return the position of the smallest element in the range a[from] . . .
     *         a[a.length - 1]
     */
    private static int minimumPosition(int[] a, int from)
    {
        int minPos = from;
        for (int i = from + 1; i < a.length; i++) {
            if (a[i] < a[minPos]) {
                minPos = i;
            }
        }
        return minPos;
    }
}